JP6007155B2 - Development processing method, program, computer storage medium, and development processing apparatus - Google Patents

Description

  The present invention relates to a development processing method, a program, a computer storage medium, and a development processing apparatus for developing a substrate on which a resist film is formed to form a predetermined pattern on the substrate.

  For example, in a photolithography process in a semiconductor device manufacturing process, for example, a resist coating process is performed on a semiconductor wafer (hereinafter referred to as “wafer”) to form a resist film, and a predetermined pattern is exposed on the resist film. An exposure process, a heating process (post-exposure baking) for promoting a chemical reaction in the resist film after the exposure, a developing process for developing the exposed resist film, and the like are sequentially performed to form a predetermined resist pattern on the wafer.

  Incidentally, in recent years, in order to further increase the integration of semiconductor devices, it is required to make the pattern of the film to be processed finer. For this reason, miniaturization of the resist pattern has been advanced, and for example, the light of the exposure process in the photolithography process has been shortened. However, there are technical and cost limitations to shortening the wavelength of the exposure light source, and it is difficult to form a fine resist pattern on the order of several nanometers, for example, only by the method of advancing the wavelength of light. is there.

Therefore, so-called dual tone development (DTD: Dual) is performed, in which both positive development and negative development are performed on the resist film.
Tone Development) has proposed a method of improving the resolution of a resist pattern by a factor of 2 (Patent Document 1). In this method, first, a resist film formed on the wafer W is exposed using a mask having a predetermined pattern, and then a resist pattern is formed by positive development. At this time, as shown in FIG. 11, the distribution of the exposure amount in the resist film 401 exposed through the mask 400 has a substantially sinusoidal shape, which is high in the exposed portion and low in the unexposed portion. Then, by supplying a developing solution for positive development to the resist film 401 and developing, the resist film 401 in a region where the exposure amount is higher than the predetermined value D1 is dissolved, and a predetermined resist pattern is obtained as shown in FIG. 402 is formed. After that, by supplying a developing solution for negative development to the resist pattern 402 and developing the resist pattern 402, as shown in FIG. 13, the resist pattern 402 in a region where the exposure amount is lower than a predetermined value D2 is dissolved. As a result, a resist pattern 403 having a half pitch of the pattern of the mask 400 is formed on the wafer W.

JP 2000-199953 A

  However, in the above-described method, the dimension of the resist pattern 402 after development varies, and it is difficult to form a pattern with high accuracy.

  Thus, as a result of intensive studies by the present inventors, it has been found that the dimensional variation of the resist pattern 402 is caused by negative development performed after positive development. Specifically, at the time of performing negative development, the acid generated in the exposed portion of the resist film 401 is reduced for some reason, and the acid in the exposed portion of the resist film 401 that is not originally dissolved by negative development is reduced. The reduced part was dissolved. Further examination of this point by the present inventor revealed that the decrease in acid was most significant before and after rinsing with, for example, pure water performed after positive development. This is presumably because hydrogen ions existing on the surface of the resist pattern 402 are dissolved into the pure water side when they come into contact with pure water as a rinsing liquid.

  Therefore, the present inventors have considered that if the acid lost from the resist pattern 402 can be minimized until negative development is performed, variations in the dimensions of the resist pattern 402 can be suppressed.

The present invention has been made in view of such points, and an object of the present invention is to form a pattern with high accuracy in dual tone development in which positive development and negative development are performed on a substrate on which a resist film is formed. It is aimed.

In order to achieve the above object, the present invention provides a development processing method for forming a predetermined pattern on a substrate by performing positive development and negative development after exposing the substrate on which a resist film is formed. Rinse by supplying an organic solvent that is one of ethanol, 1-propanol, isopropyl alcohol or tertiary-butyl alcohol, or a mixture of isopropyl alcohol and 1-butanol to a substrate that has been positively developed with a developer. a rinsing step for washing, then, is characterized in that chromatic and negative development step of performing negative development by supplying a negative developer in the substrate.

According to the present invention, after positive development , rinse is performed by supplying an organic solvent that is ethanol, 1-propanol, isopropyl alcohol, or tertiary-butyl alcohol, or a mixture of isopropyl alcohol and 1-butanol. I do. According to the inventor of the present invention, by using such an organic solvent, it is possible to suppress the escape of acid from the resist film during the rinse cleaning. Therefore, deprotection is performed by the acid remaining in the resist film, and a desired pattern can be obtained in the negative development process. In addition, since this organic solvent is water-soluble and is easily mixed with, for example, TMAH used for positive development, rinsing can be performed efficiently. In addition, since the organic solvent does not dissolve the unexposed portion of the resist film, the dimensional accuracy of the resist pattern is not affected during the rinse cleaning.

  The concentration of 1-butanol in the mixed solution of isopropyl alcohol and 1-butanol may be 60% or less.

  According to another aspect of the present invention, there is provided a program that operates on a computer of a control unit that controls the development processing apparatus in order to cause the development processing apparatus to execute the development processing method.

  According to another aspect of the present invention, a readable computer storage medium storing the program is provided.

Furthermore, the present invention according to another aspect is a development processing apparatus for performing a positive development and a negative development after exposing a substrate on which a resist film is formed to form a predetermined pattern on the substrate. For a first supply section for supplying a developer and a substrate positively developed with a positive developer, either ethanol, 1-propanol, isopropyl alcohol or tertiary-butyl alcohol, or isopropyl alcohol and 1 A rinsing solution supply unit for supplying an organic solvent that is a mixture of butanol, and a negative developing solution for supplying a negative developing solution to a substrate that has been positively developed with a positive developing solution and then rinsed with the organic solvent . It is characterized in that chromatic and second supply unit.

  The concentration of 1-butanol in the mixed solution of isopropyl alcohol and 1-butanol may be 60% or less.

  According to the present invention, a pattern can be formed with high accuracy in dual tone development in which positive development and negative development are performed on a substrate on which a resist film is formed.

It is a top view which shows the outline of a structure of the substrate processing system concerning this Embodiment. It is a side view which shows the outline of a structure of the substrate processing system concerning this Embodiment. It is a side view which shows the outline of a structure of the substrate processing system concerning this Embodiment. It is a longitudinal cross-sectional view which shows the outline of a structure of a development processing apparatus. It is a cross-sectional view which shows the outline of a structure of a development processing apparatus. It is a perspective view which shows the outline of a structure of a coating nozzle. It is the flowchart explaining the main processes of wafer processing. It is explanatory drawing of the longitudinal cross-section which shows a mode that the resist pattern was formed on the wafer by positive image development. It is explanatory drawing of the longitudinal cross-section which shows the mode of the resist pattern which performed negative development further on the resist pattern after positive development. It is explanatory drawing of the longitudinal cross-section which shows the mode of the resist pattern formed by performing positive image development and negative image development to the resist film at the time of increasing exposure amount. It is explanatory drawing which shows distribution of the exposure amount in a resist film. It is explanatory drawing which shows a mode that the resist pattern was formed on the wafer by positive image development. It is explanatory drawing which shows a mode that the resist pattern was formed on the wafer by negative image development after positive image development.

  Embodiments of the present invention will be described below. FIG. 1 is an explanatory diagram showing an outline of the configuration of a substrate processing system 1 that performs the substrate processing method according to the present embodiment. 2 and 3 are side views showing an outline of the internal configuration of the substrate processing system 1.

  As shown in FIG. 1, the substrate processing system 1 includes a cassette station 10 in which a cassette C containing a plurality of wafers W is loaded and unloaded, and a processing station 11 having a plurality of various processing apparatuses for performing predetermined processing on the wafers W. And an interface station 13 that transfers the wafer W to and from the exposure apparatus 12 adjacent to the processing station 11 is integrally connected.

  The cassette station 10 is provided with a cassette mounting table 20. The cassette mounting table 20 is provided with a plurality of cassette mounting plates 21 on which the cassette C is mounted when the cassette C is carried into and out of the substrate processing system 1.

  As shown in FIG. 1, the cassette station 10 is provided with a wafer transfer device 23 that is movable on a transfer path 22 that extends in the X direction. The wafer transfer device 23 is also movable in the vertical direction and the vertical axis direction (θ direction), and includes a cassette C on each cassette mounting plate 21 and a delivery device for a third block G3 of the processing station 11 described later. The wafer W can be transferred between the two.

  The processing station 11 is provided with a plurality of, for example, four blocks G1, G2, G3, and G4 having various devices. For example, the first block G1 is provided on the front side of the processing station 11 (X direction negative direction side in FIG. 1), and the second block is provided on the back side of the processing station 11 (X direction positive direction side in FIG. 1). Block G2 is provided. A third block G3 is provided on the cassette station 10 side (Y direction negative direction side in FIG. 1) of the processing station 11, and the interface station 13 side (Y direction positive direction side in FIG. 1) of the processing station 11 is provided. Is provided with a fourth block G4.

  For example, in the first block G1, as shown in FIG. 2, a plurality of liquid processing apparatuses, for example, a development processing apparatus 30 that develops the wafer W, an antireflection film (hereinafter referred to as “lower antireflection”) under the resist film of the wafer W. A lower antireflection film forming device 31 for forming a film), a resist coating device 32 for applying a resist solution to the wafer W to form a resist film, and an antireflection film (hereinafter referred to as “upper reflection” on the resist film of the wafer W). An upper antireflection film forming device 33 for forming an “antireflection film” is arranged in this order from the bottom.

  For example, three development processing devices 30, a lower antireflection film forming device 31, a resist coating device 32, and an upper antireflection film forming device 33 are arranged in a horizontal direction. The number and arrangement of the development processing device 30, the lower antireflection film forming device 31, the resist coating device 32, and the upper antireflection film forming device 33 can be arbitrarily selected.

  In the development processing device 30, the lower antireflection film forming device 31, the resist coating device 32, and the upper antireflection film forming device 33, for example, spin coating for applying a predetermined coating solution onto the wafer W is performed. In spin coating, for example, a coating liquid is discharged onto the wafer W from a coating nozzle, and the wafer W is rotated to diffuse the coating liquid to the surface of the wafer W. The configuration of these liquid processing apparatuses will be described later.

  For example, the second block G2 is provided with a plurality of heat treatment apparatuses 40 to 43 for performing heat treatment such as heating and cooling of the wafer W as shown in FIG. Each heat processing apparatus 40-43 is laminated | stacked and provided in order of the heat processing apparatuses 40-43 from the bottom.

  For example, in the third block G3, a plurality of delivery devices 50, 51, 52, 53, 54, 55, and 56 are provided in order from the bottom. The fourth block G4 is provided with a plurality of delivery devices 60, 61, 62 in order from the bottom.

  As shown in FIG. 1, a wafer transfer region D is formed in a region surrounded by the first block G1 to the fourth block G4. In the wafer transfer region D, for example, a plurality of wafer transfer devices 70 having transfer arms that are movable in the Y direction, the X direction, the θ direction, and the vertical direction are arranged. The wafer transfer device 70 moves in the wafer transfer area D and transfers the wafer W to a predetermined device in the surrounding first block G1, second block G2, third block G3, and fourth block G4. it can.

  Further, in the wafer transfer region D, a shuttle transfer device 80 that transfers the wafer W linearly between the third block G3 and the fourth block G4 is provided.

  The shuttle conveyance device 80 is linearly movable in the Y direction of FIG. 3, for example. The shuttle transfer device 80 moves in the Y direction while supporting the wafer W, and can transfer the wafer W between the transfer device 52 of the third block G3 and the transfer device 62 of the fourth block G4.

  As shown in FIG. 1, a wafer transfer apparatus 100 is provided next to the third block G3 on the positive side in the X direction. The wafer transfer apparatus 100 has a transfer arm that is movable in the X direction, the θ direction, and the vertical direction, for example. The wafer transfer device 100 can move up and down while supporting the wafer W, and can transfer the wafer W to each delivery device in the third block G3.

  The interface station 13 is provided with a wafer transfer device 110 and a delivery device 111. The wafer transfer device 110 has a transfer arm that is movable in the Y direction, the θ direction, and the vertical direction, for example. The wafer transfer device 110 can transfer the wafer W between each transfer device, the transfer device 111, and the exposure device 12 in the fourth block G4, for example, by supporting the wafer W on a transfer arm.

  Next, the configuration of the development processing apparatus 30 described above will be described. As shown in FIG. 4, the development processing apparatus 30 has a processing container 130 capable of sealing the inside. On the side surface of the processing container 130, a loading / unloading port (not shown) for the wafer W is formed.

  A spin chuck 140 that holds and rotates the wafer W is provided in the processing container 130. The spin chuck 140 can be rotated at a predetermined speed by a chuck driving unit 141 such as a motor. Further, the chuck driving unit 141 is provided with an elevating drive mechanism such as a cylinder, and the spin chuck 140 can be moved up and down.

  Around the spin chuck 140, there is provided a cup 142 that receives and collects the liquid scattered or dropped from the wafer W. A discharge pipe 143 that discharges the collected liquid and an exhaust pipe 144 that exhausts the atmosphere in the cup 142 are connected to the lower surface of the cup 142.

  As shown in FIG. 5, a rail 150 extending along the Y direction (left and right direction in FIG. 5) is formed on the X direction negative direction (downward direction in FIG. 5) side of the cup 142. The rail 150 is formed, for example, from the outside of the cup 142 in the Y direction negative direction (left direction in FIG. 5) to the outside in the Y direction positive direction (right direction in FIG. 5). For example, three arms 151, 152, and 153 are attached to the rail 150.

  The first arm 151 supports a positive developer supply nozzle 154 as a first supply unit that supplies a developer for positive development. The first arm 151 is movable on the rail 150 by a nozzle drive unit 155 shown in FIG. As a result, the positive developer supply nozzle 154 passes from above the central portion of the wafer W in the cup 142 from the standby unit 156 installed on the outer side of the cup 142 in the Y direction positive direction, to the Y direction of the cup 142. It is possible to move to a standby unit 157 provided outside the negative direction side. The first arm 151 can be moved up and down by a nozzle drive unit 155, and the height of the positive developer supply nozzle 154 can be adjusted. For example, tetramethylammonium hydroxide (TMAH) is used as the developer supplied from the positive developer supply nozzle 154.

  For example, as shown in FIG. 6, the positive developer supply nozzle 154 has an elongated shape as a whole, and its length J is configured to be at least larger than the diameter of the wafer W, for example. A slit-like discharge having a predetermined length D and a predetermined width G larger than the diameter of the wafer W, for example, along the longitudinal direction of the positive developer supply nozzle 154 is formed on the lower end surface of the positive developer supply nozzle 154. An outlet 154a is formed.

  A rinse liquid supply nozzle 158 as a rinse liquid supply unit that supplies a rinse liquid for rinsing and cleaning the wafer W is supported on the second arm 152. The second arm 152 is movable on the rail 150 by a nozzle driving unit 159 shown in FIG. Thereby, the rinsing liquid supply nozzle 158 can move from the standby unit 160 provided on the outer side of the cup 142 in the Y direction positive direction to above the center of the wafer W in the cup 142. The standby unit 160 is provided on the Y direction positive direction side of the standby unit 156. Further, the second arm 152 can be moved up and down by the nozzle driving unit 159, and the height of the rinsing liquid supply nozzle 158 can be adjusted. A rinse liquid supply source (not shown) is connected to the rinse liquid supply nozzle 158, and an organic solvent as a rinse liquid for cleaning the wafer W after positive development and a rinse liquid as a rinse liquid for cleaning the wafer W after negative development are used. For example, MIBC can be supplied to the rinsing liquid supply nozzle 158. In the present embodiment, as the organic solvent supplied from the rinse liquid supply nozzle 158, for example, a mixture of isopropyl alcohol (IPA) and 1-butanol is used. The concentration of 1-butanol in this mixed solution is adjusted to be about 60% by volume.

  The third arm 153 supports a negative developer supply nozzle 161 as a second supply unit that supplies a developer for negative development. The negative developer supply nozzle 161 has an elongated shape larger than the diameter of the wafer W, like the positive developer supply nozzle 154. The third arm 153 is movable on the rail 150 by a nozzle driving unit 162 shown in FIG. As a result, the negative developer supply nozzle 161 can move from the standby portion 163 provided outside the cup 142 on the Y direction negative direction side to above the center portion of the support wafer S in the cup 142. The standby unit 163 is provided on the Y direction negative direction side of the standby unit 157. Further, the third arm 153 can be moved up and down by the nozzle driving unit 162, and the height of the negative developer supply nozzle 161 can be adjusted.

  In such a case, in the developing apparatus 30, a positive developing solution can be supplied onto the wafer W by the positive developing solution supply nozzle 154, and further, negative development can be performed on the processing wafer W by the negative developing solution supply nozzle 161. Can be supplied, and the rinse liquid supply nozzle 158 can supply the rinse liquid to the wafer W after the developer.

  The other anti-reflective film forming apparatus 31, resist coating apparatus 32, and upper anti-reflective film forming apparatus 33, which are other liquid processing apparatuses, have the same configuration except that the shape and number of nozzles and the liquid supplied from the nozzles are different. Since the configuration is the same as that of the development processing apparatus 30 described above, a description thereof will be omitted.

  Next, selection of a rinse liquid used for rinse cleaning of the wafer W after positive development will be described.

  In dual tone development in which both positive development and negative development are performed on a resist film, it is important to properly dissolve and remove only unexposed portions in negative development. However, as described above, in the conventional dual tone development, the acid generated in the exposed portion of the resist film is greatly reduced as a result of rinsing with pure water after the positive development and before the negative development. Thus, the portion where the acid in the exposed portion is reduced during the negative development is dissolved. This decrease in acid, that is, the decrease in hydrogen ions is caused by the dissolution of hydrogen ions from the resist film into the rinse solution. The solution in which hydrogen ions are difficult to dissolve needs to be a solution having a small polarity. Further, the rinse solution after the positive development is required to be a solution that does not dissolve the exposed portion of the resist film and has little pattern collapse of the resist pattern after development. Furthermore, since the resist pattern is damaged when the developing solution and the rinsing solution are suspended, it is required to be soluble in, for example, TMAH, which is a positive developing solution, and more specifically, water-soluble. The present inventors diligently studied such a solution, and as a result, an organic solvent in which the hydrogen bond term value in the Hansen solubility parameter is at least twice the polarization term value, specifically isopropyl alcohol, tertiary-butyl alcohol. Alcohols such as were found to fall under this category.

Here, the Hansen solubility parameter (HSP: Hansen Solubility Parameter) is an index of solubility indicating how much a certain substance is dissolved in another substance. According to this index, a substance is derived from energy δ _d (dispersion term) derived from intermolecular dispersion force, energy δ _p (polarization term) derived from intermolecular polar force, and hydrogen bonding force between molecules. Characterized by energy δ _h (hydrogen bond term). The reason for not considering the dispersion term in the selection of the rinsing liquid is that the above-mentioned alcohols such as isopropyl alcohol have a smaller dispersion term than the polarization term and the hydrogen bond term, and there is almost no influence of the dispersion term. is there.

  In this embodiment, isopropyl alcohol (IPA) mixed with 1-butanol is used as a rinsing liquid after positive development. This is because isopropyl alcohol having a boiling point lower than that of water is used. This is because 1-butanol, which is an alcohol having a boiling point higher than that of water, is mixed to increase the temperature of the boiling point as the rinse liquid. Isopropyl alcohol has high volatility, and the ambient temperature of the wafer W is lowered by heat of vaporization during the drying process in the rinse cleaning. If it does so, while the water | moisture content in air | atmosphere will condense and melt | dissolve in a rinse liquid, since the boiling point of isopropyl alcohol as a rinse liquid is about 82 degreeC and water is lower, it will evaporate ahead of water. As a result, there is a problem that moisture remains on the wafer W and a so-called watermark is generated. In this respect, 1-butanol has a boiling point of about 118 ° C., which is higher than that of water. Therefore, mixing with isopropyl alcohol can increase the temperature of the boiling point as a rinsing liquid and suppress the generation of watermarks.

  The substrate processing system 1 is provided with a control unit 300 as shown in FIG. The control unit 300 is a computer, for example, and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing of the wafer W in the substrate processing system 1. The program storage unit also stores a program for controlling the operation of driving systems such as the above-described various processing apparatuses and transfer apparatuses to realize a peeling process described later in the substrate processing system 1. The program is recorded on a computer-readable storage medium such as a computer-readable hard disk (HD), flexible disk (FD), compact disk (CD), magnetic optical desk (MO), or memory card. Or installed in the control unit 300 from the storage medium.

  Next, wafer processing performed using the substrate processing system 1 configured as described above will be described. FIG. 7 is a flowchart showing an example of main steps of such wafer processing.

  First, a cassette C storing a plurality of wafers W is carried into the cassette station 10 of the substrate processing system 1, and each wafer W in the cassette C is sequentially transferred to the transfer device 53 of the processing station 11 by the wafer transfer device 23. .

  Next, the wafer W is transferred to the heat treatment apparatus 40 of the second block G2 by the wafer transfer apparatus 70 and subjected to temperature adjustment processing. Thereafter, the wafer W is transferred by the wafer transfer device 71 to the lower antireflection film forming device 31 of the first block G1, for example, and a lower antireflection film is formed on the wafer W (step S1 in FIG. 7). Thereafter, the wafer W is transferred to the heat treatment apparatus 41 of the second block G2, and heat treatment is performed.

  Thereafter, the wafer W is transferred by the wafer transfer apparatus 70 to the heat treatment apparatus 42 of the second block G2, and subjected to temperature adjustment processing. Thereafter, the wafer W is transferred to the resist coating device 32 of the first block G1 by the wafer transfer device 70, and a resist film is formed on the wafer W (step S2 in FIG. 7). Thereafter, the wafer W is transferred to the heat treatment apparatus 43 and pre-baked.

  Next, the wafer W is transferred to the upper antireflection film forming apparatus 33 of the first block G1, and an upper antireflection film is formed on the wafer W (step S3 in FIG. 7). Thereafter, the wafer W is transferred to the heat treatment apparatus 41 of the second block G2, and heat treatment is performed. Thereafter, the wafer W is transferred by the wafer transfer device 70 to the delivery device 56 of the third block G3.

    Next, the wafer W is transferred to the transfer device 52 by the wafer transfer device 100, and transferred to the transfer device 62 of the fourth block G4 by the shuttle transfer device 80. Thereafter, the wafer W is transferred to the exposure apparatus 6 by the wafer transfer apparatus 110 of the interface station 13 and subjected to exposure processing in a predetermined pattern (step S4 in FIG. 7).

  Next, the wafer W is transferred to the heat treatment apparatus 40 by the wafer transfer apparatus 70 and subjected to post-exposure baking. Thereby, the deprotection reaction is caused by the acid generated in the exposed portion of the resist film. Thereafter, the wafer W is transferred to the development processing apparatus 30 by the wafer transfer apparatus 70.

  In the development processing apparatus 30, first, for example, TMAH is supplied to the wafer W by the positive developer supply nozzle 154 as a developer for positive development, and a positive development process is performed (step S5 in FIG. 7). As a result, as shown in FIG. 8, the exposed portion of the resist film, that is, the portion where the exposure amount is greater than D1 is dissolved, and a predetermined resist pattern 200 is formed on the wafer W.

  Next, in the development processing apparatus 30, a mixed liquid of isopropyl alcohol and 1-butanol is supplied as a rinse liquid from the rinse liquid supply nozzle 158 while rotating the wafer W at a predetermined rotational speed (step S6 in FIG. 7). As a result, the resist dissolved with the developer is washed away, and the acid lost from the resist pattern 200 is minimized.

  Thereafter, the rotation of the wafer W is stopped, and negative developing processing is performed by supplying, for example, butyl acetate as a developing solution for positive development to the wafer W from the negative developing solution supply nozzle 161 ((step of FIG. 7). S7) As a result, a portion of the unexposed portion of the resist pattern 200 where the exposure amount is smaller than the predetermined value D2 is dissolved, in other words, the acid concentration in the resist pattern 200 is smaller than the predetermined value. The portion thus formed is dissolved in a negative developer, and as shown in FIG. 9, for example, a resist pattern 201 having a pattern pitch about half that of the resist pattern after positive development is formed.

  Thereafter, for example, MIBC is supplied as a rinsing liquid after negative development from the rinsing liquid supply nozzle 158 while rotating the wafer W at a predetermined number of revolutions ((Step S8 in FIG. 7). The resist is washed away.

  After the completion of the negative development, the wafer W is transferred to the heat treatment apparatus 42 by the wafer transfer apparatus 70 and subjected to a post baking process. Next, the temperature of the wafer W is adjusted by the heat treatment apparatus 43. Thereafter, the wafer W is transferred to the cassette C of the predetermined cassette mounting plate 21 via the wafer transfer device 70 and the wafer transfer device 23, and a series of photolithography steps is completed.

  According to the above embodiment, after the positive development, the organic solvent whose hydrogen bond term in the Hansen solubility parameter is twice or more the polarization term is supplied for the rinse cleaning. It is possible to suppress the escape of acid from the pattern 200. As a result, deprotection is performed by the acid remaining in the resist pattern 200, and a desired pattern can be obtained in a negative development process performed thereafter. Further, since a water-soluble organic solvent is used as the rinsing liquid, it easily mixes with, for example, TMAH used for positive development. Therefore, it is possible to prevent the developing solution and the rinsing solution from being suspended, and the resist pattern 200 from being damaged. In addition, since this rinse solution does not dissolve the unexposed portion of the resist film, the dimensional accuracy of the resist pattern 200 is not affected during the rinse cleaning. Therefore, so-called dual tone development can be performed with high accuracy.

  In addition, when pure water is used for rinsing, charges are charged on the surface of the wafer W, thereby adsorbing foreign matter, which may cause defects. In this regard, by using an organic solvent as in the present embodiment, it is possible to avoid the surface of the wafer W from being charged, so that the occurrence of defects due to foreign matters can be reduced.

  In addition, the rinse cleaning after development is performed for a long time as long as possible in terms of the throughput of the wafer processing from the viewpoint of reliably removing the developer and the dissolved product of the resist generated by the developer from the wafer W. Is preferred. However, it is not preferable to perform rinsing with pure water for a long time as in the prior art because the amount of acid that escapes from the resist pattern 200 increases in proportion to the length of the cleaning time. However, if the rinse cleaning time is shortened in consideration of the loss of acid, defects will increase due to the fact that the dissolved product of the resist remains on the wafer W. In this regard, if an organic solvent is used as in the present embodiment, the amount of acid that escapes even after long-time rinse cleaning can be suppressed, so that the wafer W can be reliably cleaned and defects caused by insufficient rinse cleaning. Can be reduced.

  Note that, in the rinsing cleaning after the positive development process (step S6), as a countermeasure against the loss of acid from the resist pattern 200, the exposure amount to the resist film is increased, and the amount of acid generated in the entire resist film is increased. It is also possible. However, even if the exposure amount is increased from the state of FIG. 8, for example, as shown in FIG. 10, only the positions of the region where the exposure amount is higher than the predetermined value D1 and the region lower than the predetermined value D2 are changed. Yes, even if the exposure amount is changed, the line width itself of the resist patterns 200 and 201 cannot be changed. Therefore, it is important in dual tone development to suppress acid decrease from the resist pattern 200 during the rinse cleaning process as in the present invention.

  In the above embodiment, as the rinsing liquid after the positive development, a mixed liquid of isopropyl alcohol and 1-butanol in which the ratio of 1-butanol is about 60% by volume is used. Of course, single isopropyl alcohol may be used from the viewpoint of suppressing acid escape from the resist pattern 200 during rinsing, being water-soluble, and not dissolving unexposed portions of the resist film. However, if a solvent having a low boiling point such as isopropyl alcohol is used as described above, a watermark is caused. Therefore, it is more preferable to use a solvent mixed with a solvent having a higher boiling point than water such as 1-butanol.

  When a mixed solution of isopropyl alcohol and 1-butanol is used, if the proportion of 1-butanol is about 60% or less in volume ratio, the mixed solution of isopropyl alcohol and 1-butanol is TMAH which is a positive developer. It becomes soluble. Therefore, the proportion of 1-butanol in the mixed solution of isopropyl alcohol and 1-butanol is preferably about 60% or less by volume ratio.

In the above embodiment, alcohols such as isopropyl alcohol and tertiary-butyl alcohol are exemplified as the organic solvent in which the hydrogen bond term value in the Hansen solubility parameter is twice or more the polarization term value. but as other alcohols, for example ethanol, 1-propanol or the like may be used. Since these alcohols also have a boiling point lower than that of water, they are preferably mixed with a solvent having a boiling point higher than that of water, such as 1-butanol.

  In general, when two substances are mixed, the HSP value is a value between the two substances according to the mixing ratio. As an example, when two substances are mixed at a ratio of 1: 1, the HSP value is approximately an intermediate value between the two substances. In other words, even if solutions having a hydrogen bond term value of Hansen's solubility parameter that is more than twice the polarization term value are mixed, the hydrogen bond term value of the solution after mixing is still the polarization term value. It remains over twice. Accordingly, a mixture of solvents such as isopropyl alcohol, tertiary-butyl alcohol, methanol, ethanol, and 1-propanol at an arbitrary ratio may be used as the rinsing liquid after the positive development. Even in such a case, a mixture of alcohol having a high boiling point such as 1-butanol may be used as the rinsing liquid. However, as described above, the rinse solution is preferably soluble with TMAH, which is a positive developer, and when mixed with alcohol having a high boiling point such as 1-butanol, the mixed solution is TMAH. It is preferable to adjust the amount to be mixed so as to be soluble in water. In such a case, the mixing ratio is obtained by conducting a test or the like in advance.

  In addition to 1-butanol, for example, the number of carbon atoms is 4 or more as an alcohol to be mixed in order to increase the boiling point of an organic solvent in which the hydrogen bond term in Hansen's solubility parameter is twice or more the polarization term. Any alcohol having a boiling point higher than that of water can be suitably used. Examples include isobutanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2 -Alcohols such as methyl-1-pentanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol and 3-heptanol correspond to this.

  In the above embodiment, after the rinse cleaning is performed in step S6, the negative development processing is continuously performed in the development processing apparatus 30 in step S7. However, between the rinse cleaning in step S6 and the development processing in step S7. The wafer W may be heat-treated, and the resist pattern 200 may be subjected to a crosslinking reaction with the acid remaining in the resist pattern 200. By doing so, it is possible to further suppress dissolution of the exposed portion during negative development, and it is possible to perform more accurate dual tone development. In such a case, the positive development in step S5 and the negative development in step S7 may be performed by different development processing apparatuses 30. Further, the development processing device 30 for positive development and the development processing device 30 for negative development may be provided separately.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the idea described in the claims, and these naturally belong to the technical scope of the present invention. It is understood. The present invention is not limited to this example and can take various forms. The present invention can also be applied to a case where the substrate is another substrate such as an FPD (flat panel display) other than a wafer or a mask reticle for a photomask.

  The present invention is useful when performing substrate processing using dual tone development.

DESCRIPTION OF SYMBOLS 1 Substrate processing system 30 Development processing apparatus 31 Lower antireflection film forming apparatus 32 Resist coating apparatus 33 Upper antireflection film forming apparatus 40 Heat processing apparatus 154 Positive type developing solution supply nozzle 158 Rinse solution supplying nozzle 161 Negative type developing solution supply nozzle 200 Resist Pattern 201 Resist pattern W Wafer

Claims (6)

A development processing method of performing a positive development and a negative development after exposing a substrate on which a resist film is formed, and forming a predetermined pattern on the substrate,
An organic solvent that is ethanol, 1-propanol, isopropyl alcohol or tertiary-butyl alcohol, or a mixture of isopropyl alcohol and 1-butanol is supplied to a substrate positively developed with a positive developer. Rinsing process for rinsing,
Thereafter, the organic and negative development step of performing negative development by supplying a negative developer to the substrate, and wherein the development processing method. The development processing method according to claim 1 , wherein the concentration of 1-butanol in the mixed solution of isopropyl alcohol and 1-butanol is 60% or less. For execution by the developing unit the developing method according to claim 1 or 2, a program running on a computer of a control unit for controlling the developing apparatus. A readable computer storage medium storing the program according to claim 3 . A development processing apparatus that performs positive development and negative development after exposing a substrate on which a resist film is formed, and forms a predetermined pattern on the substrate,
A first supply unit for supplying a positive developer to the substrate;
Supplying an organic solvent that is either ethanol, 1-propanol, isopropyl alcohol or tertiary-butyl alcohol, or a mixture of isopropyl alcohol and 1-butanol to a substrate that has been positively developed with a positive developer. A rinsing liquid supply unit,
A substrate that has been rinsed with the organic solvent after being positive development by positive developer, characterized by chromatic and a second supply unit for supplying a negative developer, developing apparatus. 6. The development processing apparatus according to claim 5 , wherein the concentration of 1-butanol in the mixed solution of isopropyl alcohol and 1-butanol is 60% or less.

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